Shift and shift lock and release mechanisms that are commonly employed on known keyboards are unduly complex and result in excessive manufacturing and assembly costs. The present invention provides a keyboard shift and shift lock and release mechanism which utilizes three keyswitches and the entire assembly is only slightly more expensive than the keyswitches themselves. Moreover, the assembly cost of the mechanism of this invention is essentially the same as the cost of inserting three standard keyswitches into the keyboard and, hence, it is minimal. These advantages flow from the simple, uncomplicated design of the present invention. In addition, the operating force for the shift and shift lock keyswitches of this keyboard is essentially the same as for any other keyswitch of the keyboard and, therefore, the excessive operating pressure which is commonly required to operate prior mechanisms of the described type is avoided by the improved design of the present invention.
The keyswitches of this invention have a cam formed on their actuating plunger which interact with the cam follower of a slide member on the housing of the associated keyswitch.
Another type of switch which utilizes a cam that is formed on a plunger and a slide member which carries a cam follower is shown in U.S. Pat. No. 3,882,295, issued in the name of Robert Christen Madland on May 6, 1975 and assigned to the assignee of the present invention. This type of switch, however, is not designed to provide or to be used with a keyboard shift and shift lock mechanism.